This guide will help you with installing Snorby on a freshly installed Ubuntu 12.04 LTS server. We’ll be using the latest version from the git repository.

Install required dependencies

Snorby uses a number of libraries and tools. They should be installed before we’re going to install Snorby.

# apt-get install apache2 git imagemagick wkhtmltopdf ruby1.9.3 libyaml-dev libxml2-dev libxslt1-dev  zlib1g-dev build-essential openssl libssl-dev libmysqlclient-dev libreadline6-dev
# gem install rails
# gem update

Install snorby

We’re going to fetch the latest version from Snorby from the Git tree.

git clone http://github.com/Snorby/snorby.git

Once snorby is downloaded, we proceed by installing a few dependencies.

# cd snorby && bundle install

Create 2 config files

You have to create 2 files in the config/ directory. First file is called database.yml and this is the contents.

# Snorby Database Configuration
#
# Please set your database password/user below
# NOTE: Indentation is important.
#
snorby: &snorby
  adapter: mysql
  username: snorby
  password: "s3cr3t"
  host: 127.0.0.1 # or the IP of your database server

development:
  database: snorby
  <

The second file is snorby_config.yml

production:
  domain: 'snorby.yourdomain.com' # can be changed to your domain
  wkhtmltopdf: /usr/bin/wkhtmltopdf # correct for Ubuntu 12.04
  ssl: false
  mailer_sender: 'snorby@yourdomain.com'  # can be changed 
  geoip_uri: "http://geolite.maxmind.com/download/geoip/database/GeoLiteCountry/GeoIP.dat.gz"
  rules:
    - ""
  authentication_mode: database

Create database account

Before proceeding you have to create a database user that can connect from the snorby machine to your MySQL server. You also need to create a new database and give full rights for the new user to the new database. The user should and the database should be called “snorby”. The password should be the same password as the one used in “database.yml”.

Run the setup program for Snorby

The command should finalize the installation of Snorby on your system.

# bundle exec rake snorby:setup

Final step : run Snorby

This command will start Snorby without detaching from the console. It’s a good idea to use this the first time so you can check if any errors are reported.

bundle exec rails server -e production

If you didn’t get any errors, you should be able to access your Snorby installation using the following URL. This assumes you running Snorby and your webbrowser on the same machine. Adapt to your needs if necessary.

http://localhost:3000

The default login is ‘snorby@snorby.org’. Password is ‘snorby’. You’ll notice that the database is still empty. You’ll need a tool like Barnyard2 to send events from Snort to your Snorby database.

Configuring Barnyard2 event feed

This assumes you’ve installed Barnyard2 as described in this post. Add the following line to your /etc/snort/barnyard2.conf config file.

output database: log, mysql, user=snorby password=s3cr3t dbname=snorby host=localhost

Adapt the password and the host if necessary. They should match the database and password you used in the database.yml configuration file.
After restarting barnyard2, events will start to pop up in the GUI.

This howto will explain how to install snort on Ubuntu 12.04. We start from an Ubuntu server with 2 interfaces. eth0 is the management interface. eth1 is the dedicated sniffing interface. The sensor is not inline. eth1 will be connected to a mirror port on the switch. I’m using a software switch called Open vSwitch. More info in this post. Of course you can also connect the interface to a physical port on a hardware switch. Just make sure to configure to port in mirror or SPAN mode.

Prepare the OS

By default, the unused interface eth1 will stay down. By adding the following to /etc/network/interfaces , the interface will be enabled at boot time.

auto eth1
iface eth1 inet manual
        up ifconfig $IFACE up

After rebooting the machine, the interface should be enabled automatically. You can now use tcpdump to test if the interface is UP. tcpdump should return a lot of traffic. That means that the mirror port is also working as expected.

 # tcpdump -ni eth1

Install Snort

The following command will download and install snort on your machine.

apt-get install snort

Proceed with answering all questions that popup during the installation process.

Adapt the default installation

After the installation, edit /etc/snort/snort.conf . Make sure to comment out all lines that start with ‘output’. Copy and paste the following output setting to your configuration file. If you forget this, you’ll have problems with Barnyard2.

output unified2: filename merged.log, limit 128

Also edit /etc/snort/snort.debian.conf and set the interface to eth1 instead of the default eth0

DEBIAN_SNORT_INTERFACE="eth1"

Reboot

Now it’s best to reboot the machine to make sure that you’re machine boots fine and automatically start snort to do intrusion detection on the network.

# reboot

After logging in, have a look in /var/log/snort/merged.conf . If all is well, it should log suspicious traffic to that file.

Install up-to-date rules

We’ve done everything to install snort on our machine. In the next post, I’ll explain how to install some up-to-date rules. This is necessary to make sure Snort is able to detect the latest threats.
This page is part of a series about a complete installation and configuration of Snort.

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